Raúl Castro has made sweeping changes to Cuba's cabinet, cementing his authority and sidelinining proteges of his brother Fidel.

The president promoted allies from the military to key positions in an unprecedented shake-up which replaced eight ministers and exposed Fidel's waning influence.

The highest-profile casualties were Felipe Perez Roque, who was removed as foreign minister, and Carlos Lage, who was replaced as chief cabinet minister. Lage will retain his other post as vice president of the council of state. Both are veteran members of Fidel's inner circle.

Analysts said the reshuffle did not necessarily augur policy changes and that Raúl, 77, was likely to continue cautious attempts to reform the communist island's moribund economy.

The shake-up was announced in a bland statement on state-run television, made after sports and weather updates, which played down its significance. The personnel changes, along with the merging of several ministries, were aim at "gradually reducing" the government's size, it said.

Since taking over from his ailing brother in 2006 Raúl, who served as defence minister since the revolution's triumph half a century ago, has promised to trim bureaucracy and loosen state controls on economic activity.

It is unclear to what extent Fidel, 82, remains involved in policymaking. Last week he reportedly left his hospital bed and astonished onlookers by walking in public for the first time since falling sick. "Fidel went out and they saw him, Fidel walking in the streets in Havana," said Venezuela's president, Hugo Chávez. "A miracle. The people cried."

The "maximum leader" reportedly walked slowly, looked at his feet and wore shorts, white socks pulled up high and a tracksuit top. Cuban officials supplied no details of the stroll. There was no suggestion it marked a dramatic improvement in his health.

The ousting of Perez Roque, 43, and demotion of Lage, 57, marked a purge of "Fidelista Talibans" and the start of the "Raúl era", said Cuba Democracy Now, a dissident group.

Lage, architect of Cuba's economic opening in the 1990s, was widely considered a reformer, suggesting the president wanted to put his own stamp on efforts to modernise.

Filling many of the gaps are military men and technocrats Raul worked closely with for decades. The army has a reputation as one of the Caribbean island's more efficient and effective institutions. It runs swathes of the economy and is now dominant in the cabinet.

The reshuffle comes on the back of diplomatic successes which bolstered Cuba's ties to China, Latin America and Russia. But plunging tourism and nickel revenues and disappointing sugar production have compounded economic woes.

In a newspaper column Fidel said he was consulted about the reshuffle and denied his allies were moved to make way for his brother's favourites.

In an apparent reference to Lage and Perez Roque, whom he did not name, the former president said they were sidelined because the "honey of power" had stirred "undignified" delusions about improved ties with the United States.